Miscanthus is a C4 perennial rhizomatous grass with origins in Eastern Asia. Several key species and their interspecific hybrids have demonstrated the potential to produce high biomass yields in a wide range of climates. Research on all aspects of Miscanthus has accelerated rapidly in the past 20 years. In this review we present the current state of knowledge on taxonomy, physiology, breeding, cultivation and environmental impact. We draw attention to many practical aspects to be considered in developing Miscanthus for bioenergy purposes including key bottlenecks that define the research themes for the future.